Which of the following statements on Linux are correct

The apropos command runs a case insensitive search in packages descriptions for its argument.

The chmod $765$ somefile will grant the owner the right to execute, where the owner's group and others will not be able to execute the file somefile.

In $/$etc$/$my$.$cnf adding a line port$=$someportnumber allows mysql database to run on the port with value someportnumber $($if the firewall has a specific rule allowing tcp connections on that port and the port is added to mysql service with semanage command$).$

In bash the command $\text{'}$ls of$\text{'}$ will list all open files.